/*
 * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//httpclient/src/java/org/apache/commons/httpclient/params/HttpConnectionParams.java,v 1.6 2004/09/15 20:32:21 olegk Exp $
 * $Revision: 480424 $
 * $Date: 2006-11-29 06:56:49 +0100 (Wed, 29 Nov 2006) $
 *
 * ====================================================================
 *
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package org.apache.commons.httpclient.params;

/**
 * This class represents a collection of HTTP protocol parameters applicable to
 * {@link org.apache.commons.httpclient.HttpConnection HTTP connections}.
 * Protocol parameters may be linked together to form a hierarchy. If a
 * particular parameter value has not been explicitly defined in the collection
 * itself, its value will be drawn from the parent collection of parameters.
 * 
 * @author <a href="mailto:oleg@ural.ru">Oleg Kalnichevski</a>
 * 
 * @version $Revision: 480424 $
 * 
 * @since 3.0
 */
public class HttpConnectionParams extends DefaultHttpParams {

	/**
	 * Defines the default socket timeout (<tt>SO_TIMEOUT</tt>) in milliseconds
	 * which is the timeout for waiting for data. A timeout value of zero is
	 * interpreted as an infinite timeout. This value is used when no socket
	 * timeout is set in the {@link HttpMethodParams HTTP method parameters}.
	 * <p>
	 * This parameter expects a value of type {@link Integer}.
	 * </p>
	 * 
	 * @see java.net.SocketOptions#SO_TIMEOUT
	 */
	public static final String SO_TIMEOUT = "http.socket.timeout";

	/**
	 * Determines whether Nagle's algorithm is to be used. The Nagle's algorithm
	 * tries to conserve bandwidth by minimizing the number of segments that are
	 * sent. When applications wish to decrease network latency and increase
	 * performance, they can disable Nagle's algorithm (that is enable
	 * TCP_NODELAY). Data will be sent earlier, at the cost of an increase in
	 * bandwidth consumption.
	 * <p>
	 * This parameter expects a value of type {@link Boolean}.
	 * </p>
	 * 
	 * @see java.net.SocketOptions#TCP_NODELAY
	 */
	public static final String TCP_NODELAY = "http.tcp.nodelay";

	/**
	 * Determines a hint the size of the underlying buffers used by the platform
	 * for outgoing network I/O. This value is a suggestion to the kernel from
	 * the application about the size of buffers to use for the data to be sent
	 * over the socket.
	 * <p>
	 * This parameter expects a value of type {@link Integer}.
	 * </p>
	 * 
	 * @see java.net.SocketOptions#SO_SNDBUF
	 */
	public static final String SO_SNDBUF = "http.socket.sendbuffer";

	/**
	 * Determines a hint the size of the underlying buffers used by the platform
	 * for incoming network I/O. This value is a suggestion to the kernel from
	 * the application about the size of buffers to use for the data to be
	 * received over the socket.
	 * <p>
	 * This parameter expects a value of type {@link Integer}.
	 * </p>
	 * 
	 * @see java.net.SocketOptions#SO_RCVBUF
	 */
	public static final String SO_RCVBUF = "http.socket.receivebuffer";

	/**
	 * Sets SO_LINGER with the specified linger time in seconds. The maximum
	 * timeout value is platform specific. Value <tt>0</tt> implies that the
	 * option is disabled. Value <tt>-1</tt> implies that the JRE default is
	 * used. The setting only affects socket close.
	 * <p>
	 * This parameter expects a value of type {@link Integer}.
	 * </p>
	 * 
	 * @see java.net.SocketOptions#SO_LINGER
	 */
	public static final String SO_LINGER = "http.socket.linger";

	/**
	 * Determines the timeout until a connection is etablished. A value of zero
	 * means the timeout is not used. The default value is zero.
	 * <p>
	 * This parameter expects a value of type {@link Integer}.
	 * </p>
	 */
	public static final String CONNECTION_TIMEOUT = "http.connection.timeout";

	/**
	 * Determines whether stale connection check is to be used. Disabling stale
	 * connection check may result in slight performance improvement at the risk
	 * of getting an I/O error when executing a request over a connection that
	 * has been closed at the server side.
	 * <p>
	 * This parameter expects a value of type {@link Boolean}.
	 * </p>
	 */
	public static final String STALE_CONNECTION_CHECK = "http.connection.stalecheck";

	/**
	 * Creates a new collection of parameters with the collection returned by
	 * {@link #getDefaultParams()} as a parent. The collection will defer to its
	 * parent for a default value if a particular parameter is not explicitly
	 * set in the collection itself.
	 * 
	 * @see #getDefaultParams()
	 */
	public HttpConnectionParams() {
		super();
	}

	/**
	 * Returns the default socket timeout (<tt>SO_TIMEOUT</tt>) in milliseconds
	 * which is the timeout for waiting for data. A timeout value of zero is
	 * interpreted as an infinite timeout. This value is used when no socket
	 * timeout is set in the {@link HttpMethodParams HTTP method parameters}.
	 * 
	 * @return timeout in milliseconds
	 */
	public int getSoTimeout() {
		return getIntParameter(SO_TIMEOUT, 0);
	}

	/**
	 * Sets the default socket timeout (<tt>SO_TIMEOUT</tt>) in milliseconds
	 * which is the timeout for waiting for data. A timeout value of zero is
	 * interpreted as an infinite timeout. This value is used when no socket
	 * timeout is set in the {@link HttpMethodParams HTTP method parameters}.
	 * 
	 * @param timeout
	 *            Timeout in milliseconds
	 */
	public void setSoTimeout(int timeout) {
		setIntParameter(SO_TIMEOUT, timeout);
	}

	/**
	 * Determines whether Nagle's algorithm is to be used. The Nagle's algorithm
	 * tries to conserve bandwidth by minimizing the number of segments that are
	 * sent. When applications wish to decrease network latency and increase
	 * performance, they can disable Nagle's algorithm (that is enable
	 * TCP_NODELAY). Data will be sent earlier, at the cost of an increase in
	 * bandwidth consumption.
	 * 
	 * @param value
	 *            <tt>true</tt> if the Nagle's algorithm is to NOT be used (that
	 *            is enable TCP_NODELAY), <tt>false</tt> otherwise.
	 */
	public void setTcpNoDelay(boolean value) {
		setBooleanParameter(TCP_NODELAY, value);
	}

	/**
	 * Tests if Nagle's algorithm is to be used.
	 * 
	 * @return <tt>true</tt> if the Nagle's algorithm is to NOT be used (that is
	 *         enable TCP_NODELAY), <tt>false</tt> otherwise.
	 */
	public boolean getTcpNoDelay() {
		return getBooleanParameter(TCP_NODELAY, true);
	}

	/**
	 * Returns a hint the size of the underlying buffers used by the platform
	 * for outgoing network I/O. This value is a suggestion to the kernel from
	 * the application about the size of buffers to use for the data to be sent
	 * over the socket.
	 * 
	 * @return the hint size of the send buffer
	 */
	public int getSendBufferSize() {
		return getIntParameter(SO_SNDBUF, -1);
	}

	/**
	 * Sets a hint the size of the underlying buffers used by the platform for
	 * outgoing network I/O. This value is a suggestion to the kernel from the
	 * application about the size of buffers to use for the data to be sent over
	 * the socket.
	 * 
	 * @param size
	 *            the hint size of the send buffer
	 */
	public void setSendBufferSize(int size) {
		setIntParameter(SO_SNDBUF, size);
	}

	/**
	 * Returns a hint the size of the underlying buffers used by the platform
	 * for incoming network I/O. This value is a suggestion to the kernel from
	 * the application about the size of buffers to use for the data to be
	 * received over the socket.
	 * 
	 * @return the hint size of the send buffer
	 */
	public int getReceiveBufferSize() {
		return getIntParameter(SO_RCVBUF, -1);
	}

	/**
	 * Sets a hint the size of the underlying buffers used by the platform for
	 * incoming network I/O. This value is a suggestion to the kernel from the
	 * application about the size of buffers to use for the data to be received
	 * over the socket.
	 * 
	 * @param size
	 *            the hint size of the send buffer
	 */
	public void setReceiveBufferSize(int size) {
		setIntParameter(SO_RCVBUF, size);
	}

	/**
	 * Returns linger-on-close timeout. Value <tt>0</tt> implies that the option
	 * is disabled. Value <tt>-1</tt> implies that the JRE default is used.
	 * 
	 * @return the linger-on-close timeout
	 */
	public int getLinger() {
		return getIntParameter(SO_LINGER, -1);
	}

	/**
	 * Returns linger-on-close timeout. This option disables/enables immediate
	 * return from a close() of a TCP Socket. Enabling this option with a
	 * non-zero Integer timeout means that a close() will block pending the
	 * transmission and acknowledgement of all data written to the peer, at
	 * which point the socket is closed gracefully. Value <tt>0</tt> implies
	 * that the option is disabled. Value <tt>-1</tt> implies that the JRE
	 * default is used.
	 * 
	 * @param value
	 *            the linger-on-close timeout
	 */
	public void setLinger(int value) {
		setIntParameter(SO_LINGER, value);
	}

	/**
	 * Returns the timeout until a connection is etablished. A value of zero
	 * means the timeout is not used. The default value is zero.
	 * 
	 * @return timeout in milliseconds.
	 */
	public int getConnectionTimeout() {
		return getIntParameter(CONNECTION_TIMEOUT, 0);
	}

	/**
	 * Sets the timeout until a connection is etablished. A value of zero means
	 * the timeout is not used. The default value is zero.
	 * 
	 * @param timeout
	 *            Timeout in milliseconds.
	 */
	public void setConnectionTimeout(int timeout) {
		setIntParameter(CONNECTION_TIMEOUT, timeout);
	}

	/**
	 * Tests whether stale connection check is to be used. Disabling stale
	 * connection check may result in slight performance improvement at the risk
	 * of getting an I/O error when executing a request over a connection that
	 * has been closed at the server side.
	 * 
	 * @return <tt>true</tt> if stale connection check is to be used,
	 *         <tt>false</tt> otherwise.
	 */
	public boolean isStaleCheckingEnabled() {
		return getBooleanParameter(STALE_CONNECTION_CHECK, true);
	}

	/**
	 * Defines whether stale connection check is to be used. Disabling stale
	 * connection check may result in slight performance improvement at the risk
	 * of getting an I/O error when executing a request over a connection that
	 * has been closed at the server side.
	 * 
	 * @param value
	 *            <tt>true</tt> if stale connection check is to be used,
	 *            <tt>false</tt> otherwise.
	 */
	public void setStaleCheckingEnabled(boolean value) {
		setBooleanParameter(STALE_CONNECTION_CHECK, value);
	}
}
